the merest possibility
by scrub456
Summary: Subterfuge, flight lessons, and first kisses. Oh my. *Towel Day 2018, Part 6 of the Sherlock/HGTTG crossover*


*** Author's Note ***

Towel Day Prompt: "The mere thought hadn't even begun to speculate about the merest possibility of crossing my mind." ― Douglas Adams, The Hitchhiker's Guide to the Galaxy

Text in italics is John, bold is Arthur, and underlined is texting.

* * *

 **We're doing this.**

 _Seems so._

 **We're doing it.**

 _Yes._

 ** _Why_ are we doing it?**

He squeezes Random's hand in his right hand and Rosie's hand in his left.

 **Right.**

 _Hmmm._

 **This is…**

 _...fucking terrible?_

 **...the worst idea ever. And I once hitched a ride on that same Vogon ship.**

 _I invaded Afghanistan._

 **We didn't do those things alone.**

 _We're not technically alone now._

 **Two minds plus one body still equals outnumbered.**

 _Let's leave math out of it, and focus on our assets, yeah?_

With a sigh and a frown he watches Sherlock and Ford posturing for floor space directly in front of him. They're both talking faster, and louder, than is strictly necessary, in an effort to dissuade him. Sherlock is gesturing wildly and elbows Ford out of the way. Ford is tapping wildly at The Guide, waving the screen in his face, and knocks Sherlock back with his shoulder. They turn on each other then, voices and arguments reaching fever pitches.

Mycroft is standing stoically in front of the fireplace, watching the argument with disdain.

He lets go of the girls' hands and turns to face them. That's when he spots Zaphod in the kitchen, a tumbler in one hand, digging under the sink with the other two. He pulls out a container of turpentine, marked clearly with skulls and danger signs, sniffs it, takes a sip, pulls a face, and takes another sip.

 _Should we…_

 **I've seen him drink worse. We're better off just to let him go.**

 _He could die._

 **We'd be doing him a favor then, wouldn't we?**

"Uhm, you guys got anything else? I uh- I think this stuff's turned." Zaphod holds the turpentine up.

With a nod he points to the corner cupboard. Zaphod raises his glass, fills it half full with the good scotch, takes a sip, then tops the drink off with the turpentine.

A quick stir, and Zaphod takes a large swallow. "Now _that_ is a drink. Cheers, mate!" He pours another for his second head.

 _We… are going to die._

 **You're just now realizing this?**

John turns his attention to Rosie, pulling her to him, and kissing the top of her head. "Love you, Ro. So very much."

"Da." She sniffles but screws up her face in an attempt at courage when she sees his smile.

"There's my brave girl." He brushes her curls back from her brow and kisses her forehead and her nose. She kisses his nose in return.

Refocusing, Arthur turns to Random. He kisses her cheek and hugs her. "I'm sorry."

"No," she shakes her head and wipes at her eyes. "I should…"

"Everyone deserves to feel like they belong somewhere. I'm sorry I couldn't do that for you." He takes her hand and Rosie's and folds them together.

"It's a bad situation." It's John talking now, and they both nod, casting sidelong glances at each other. He looks over his shoulder. Sherlock and Ford are shouting at Mycroft. "Perhaps Mrs. Hudson could make some tea… Spare some biscuits or scones."

Rosie nods. "We'll go and ask her," she glances at Mycroft then gives John a quick hug. "Don't worry, Da." She leads Random downstairs to introduce her properly.

He turns back around. Mycroft, Ford, and Sherlock are all staring at him.

 _This is it then._

 **Steady on, mate.**

 _Oh,_ now _you want me to do the talking?_

There is silence. _Bastard,_ John exhales slowly.

"How much time do we have?" John asks Mycroft.

"Approximately eighteen hours. But you'll want to leave in…"

"Stop!" Sherlock cuts Mycroft off. "I'm not letting this happen."

At the same moment Ford steps right up to him. "You aren't going anywhere."

"I… I think I need a quick kip." He looks at each of the other three. "Then we can look over that file, yeah? If I'm saving humanity, I'll need to know how, won't I?"

"Of course, John… Ah, Mr. Dent... " Mycroft clears his throat and fidgets uncharacteristically.

 _Worth it. Just to see him squirm a bit._

"Arthur. Arthur, I…" Ford grabs him by the shoulders and can see his friend in the familiar face.

"Just a quick lie down. You know that always helps me think." He pulls Ford into a quick hug. It's only a bit awkward when they can't seem to figure out how to let go. Arthur gets tangled in Ford's great coat.

Ford blinks rapidly and clears his throat. "Must be something in my eye."

"Sherlock?" John steps up to his flatmate.

Sherlock closes his eyes and exhales slowly. "Don't do this."

"Sherl-"

"Please John? Please."

"Just a kip, Sherlock." John attempts a smile.

"John," there's a warning in his tone.

John pulls Sherlock into a quick, awkward embrace, and it stuns them both. He pulls away quickly, grabs his work bag, dashes up the stairs to his room, and slams the door.

 **Smooth, Watson.**

Dumping his work bag on the bed, he starts filling it with supplies. Med kit. Towel. Gun and extra clips. Paracetamol. Pants and socks.

 _I don't know what..._

 **How much longer are you gonna wait?**

 _I…You don't…_

 **What? Understand? _Fenchurch.*_**

It's uncomfortable and mortifyingly enlightening to go through someone else's memories, even if they share the same consciousness. When John finds the memories of Fenchurch, they are bittersweet. Beautiful. Too short.

 _You loved her._

 **She was my soul mate. And I - I'm me, so I don't believe in those sorts things, and…**

 _...it could ruin everything…_

 **...and probably you'll look like a fool…**

 _...and that sort of perfection could never possibly be…_

He sits on the floor where he's been digging in the closet for his travel tool kit and puts his head in his hands.

 **That's exactly what I always thought. But then she was gone, and I've never been more glad that I made a fool of myself.**

 _I…_

 **Because she loved me too.**

 _He went away too._

 **But he came back.**

 _Yes, but…_

 **She didn't. I didn't get a second chance. You may not get a third.**

 _It's not that simple. It was_ never _that simple._

 **You don't have to tell me. In the same head, remember?**

 _Now it's too late. We may never come back._

 **Wouldn't it have been better if you'd known the truth back then? Doesn't he deserve to know now?**

 _Have I mentioned that I hate you?_

 **It's come up. And the feeling's still mutual.**

 _But this whole thing won't work if I'm distracted, so I should…_

 **I'd rather not die because you're too busy pining away.**

 _And you're okay with… I mean, what if…_

 **It's all fine.**

 _Right._

 _What about Ford?_

 **He's my best mate. That's all.**

 _I can't do this with… There's an audience._

 **You know what's romantic? Flying.**

He laughs out loud at that as he stuffs the tool kit and a few electronic odds and ends in his bag.

 _I've never…_

 **I have. It's basically just falling.**

 _Do you think…_

 **The roof's a good place to start.**

 _I - Fuck. Yes. Let's… Fuck. Fine._ This. _This is the craziest thing I've ever done._

He silently steps into the hallway. Ford and Sherlock are still at it. He pulls down the ladder to the attic as quietly as possible, then pulls it back up after him. There's only one window, and he has to break it to get outside. He doesn't hesitate, though it's impossible to do quietly. Before he climbs out, he sends a few texts.

Don't make a fuss and don't ask questions. I need you to go to your bedroom. -J

John. -SH

Please, Sherlock. -J

And open the window. -J

He taps his mobile against his chin, then sends one to Mrs. Hudson.

Thank you for this. -J

:-)

And one more to Rosie's mobile. He hopes Ford finds it where he'd snuck it into the pocket of his great coat.

Don't drink the tea. -J

He pulls himself up to the roof, and immediately slips on some moss. He scrambles to hold on, losing his footing for the effort.

 **Let go!**

 _What? You're insane!_

 **Flying is falling. That's all. Let go!**

 _I can't…_

 **Let me.**

Arthur lets go to the sound of John swearing. It's multilingual, a bit poetic, and he can't help but laugh. He fights against John's struggle for tense control.

 **Relax or we're dead.**

John finally lets go out of desperation, and he relaxes. Arthur opens his eyes and puts out his hand. He's on his back, hovering just above the ground. His fingertips skim over the grit of the alley floor. A larger than average rock is poking him in the back.

"Fucking hell." John laughs because crying doesn't really seem appropriate.

 **Told you.**

 _You threw me off a roof. I still hate you. But… We're flying._

 **Hovering at the moment. But, yeah.**

Sherlock's window slides open above him, and he sticks his head out. He looks left, right, then up, closes his eyes and inhales. John stays perfectly still, just watching.

 **You've come this far.**

 _I don't know how…_

 **Allow me.**

He sits upright, still hovering above the ground, and slowly, silently, drifts up toward Sherlock's window, staying close to the side of the house. When Sherlock ducks back inside, he quietly follows him in.

 **I'll just be… Thinking about anything else but this.**

"Sherlock," John whispers. He's standing by the window, his feet not quite touching the floor. He can't bring himself to be bound by gravity just yet. He's just learned the impossible is actually possible, and he's going to need a bit of that to help him through this next part.

Sherlock startles, fumbles and drops his mobile, and slowly turns to face him. "John? What… _How_?"

"I need to know if you trust me." He moves closer to Sherlock, still not touching the floor. If Sherlock notices, he doesn't let on.

"John. I…" Sherlock nods slowly, as words seem to fail him.

"Here's the thing." John swallows hard. "I'm an idiot."

Sherlock laughs. John's managed to surprise him, and there's nothing contrived, nothing calculating about the laugh. It's pure and light, and it's exactly what John needs to hear. He uses his new found ability to move just a tiny bit up and in, and capture's Sherlock's laugh with a kiss.

It's short. And comparatively more chaste than most other kisses.

It's not even Earth shattering. And yet...

John expects Sherlock to freeze, locked away in his mind palace. Or fall to bits. Or, and this is most likely, to push him away.

But Sherlock just continues to laugh. He laughs, and it's still sweet. Still pure. Still the laugh only John has ever heard. And when John pulls away, Sherlock gives chase.

"I love you," John breaths against his cheek.

"John…"

"You don't have to say it back. You don't even have to feel the same thing. And it's not fair to tell you now that everything's gone to hell. Just…" He presses a kiss to Sherlock's forehead before pulling back to look him in the eyes. "I needed you to know. I love you. Always have."

Sherlock's not laughing anymore, but he's smiling. It's impossible to tell if he's noticed John's floating to even out their height difference, because his eyes are locked so intently on John's.

John thinks he doesn't need to go to space to see the cosmos.

"Took you long enough." Sherlock pulls John toward him, and the lack of resistance is what wakes him up a bit from his shock. He looks down at John's feet. He looks and he looks and he looks. And he can do the calculations as to how far John is from the floor. He knows all about mass and force and gravity and things that are constant. Things that are laws. Unchangeable.

And John is all of those things, and none of them.

Sherlock blinks a few times and keeps looking at John's feet.

"Sherlock?"

When Sherlock finally looks up, he takes a deep breath and opens his mouth. He intends to explain to John impossible things. To ask for proof this isn't a drug-addled dream. To respond to John's declaration at the very least.

What he says instead is, "I trust you."

* * *

*** A/N ***

*The love story between Arthur Dent and Fenchurch is one of the most beautiful I've ever read. I actually cried when she vanished during a hyperspace jump. Not entirely coincidentally, here's a description of Fenchurch, according to Arthur:

"She was tallish with dark hair which fell in waves around a pale and serious face. Standing still, alone, she seemed almost somber, like a statue to some important but unpopular virtue in a formal garden. She seemed to be looking at something other than what she looked as if she was looking at."

Oh... She also played cello, and her feet never quite touched the ground when she walked (but she could never actually fly until Arthur taught her).

I mean... you see it too, right?


End file.
